Answer:
The submarine is 10.4 km far from its base.
Step-by-step explanation:
Given that:
Distance traveled east = 7km
Distance traveled north = 12.5 km
This is will form a right triangle, where the distance from east to north is hypotenuse.
Here,
a = 7 , b = x and c = 12.5
Using Pythagorean theorem,
![a^2+b^2=c^2\\(7)^2+x^2=(12.5)^2\\49+x^2=156.25\\x^2=156.25-49\\x^2=107.25](https://tex.z-dn.net/?f=a%5E2%2Bb%5E2%3Dc%5E2%5C%5C%287%29%5E2%2Bx%5E2%3D%2812.5%29%5E2%5C%5C49%2Bx%5E2%3D156.25%5C%5Cx%5E2%3D156.25-49%5C%5Cx%5E2%3D107.25)
Taking square root on both sides
![\sqrt{x^2}=\sqrt{107.25}\\x=10.4](https://tex.z-dn.net/?f=%5Csqrt%7Bx%5E2%7D%3D%5Csqrt%7B107.25%7D%5C%5Cx%3D10.4)
Hence,
The submarine is 10.4 km far from its base.